In addition to identifying the proteins that have a role in underwater adhesion by marine mussels, research efforts have focused on identifying the genes responsible for the adhesive proteins, environmental factors that may influence protein production, and strategies for producing natural adhesives similar to the native mussel adhesive proteins. The production-scale availability of recombinant mussel adhesive proteins will enable researchers to formulate adhesives that are waterimpervious and ecologically safe and can bind materials ranging from glass, plastics, metals, and wood to materials, such as bone or teeth, biological organisms, and other chemicals or molecules. Unfortunately, as of yet scientists have been unable to duplicate the processes that marine mussels use to create adhesive structures. This study provides a background on adhesive proteins identified in the blue mussel, Mytilus edulis, and introduces our research interests and discusses the future for continued research related to mussel adhesion.

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Neuroendocrine adjustments to maximal and submaximal exercise were investigated in men as a function of age and training status. Twenty-four trained cyclists and 23 sedentary men constituting a young (M = 22.9 yrs, n = 16), middle-aged (M = 44.9 yrs, n = 16), and old (M = 65.5 yrs, n = 15) group performed both a maximal (GXT) and a 45-minute submaximal exercise test (cycle ergometer) at the workload corresponding to their lactate threshold. Plasma lactate, glucose, growth hormone, cortisol, norepinephrine, and epinephrine concentrations were analyzed both at rest and during exercise. Peak oxygen consumption (VO2 peak) was lower with age; however, all trained groups had higher values for VO2 peak compared to sedentary groups, regardless of age. Lactate threshold, when expressed in absolute terms, was lower with advancing age (sedentary decreases 9 and 26%: trained decreases 19 and 35% for middle-age and old, respectively, when compared to young). Pre-exercise plasma norepinephrine levels were higher with age in both trained and sedentary subjects. Cortisol levels were lower with age for sedentary subjects and were significantly elevated in trained subjects across all age groups. Endurance training resulted in increased hormonal responses, as measured by plasma concentrations, to both maximal and submaximal exercise across all age groups. However, regardless of training status, age-related declines were observed in peak responses for lactate, growth hormone, and cortisol during the GXT. During the 45-minute submaximal exercise test, these age-related differences that had been present in the GXT were abolished. This submaximal test represented a lower absolute work load for old compared to young as well as sedentary compared to trained subjects; however, individuals were working at similar relative exercise intensities. We conclude that older individuals are capable of similar hormonal responses to submaximal exercise of identical durations and intensities as their young and middle-aged counterparts, and that chronic endurance training can enhance the hormonal response to exercise in all age groups.

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